Clinton Laughrin was driving his car in Lovington, New Mexico, on
December 31, 2001, when he was stopped by Officer Brad Riley of the Lovington
Police Department. During the stop Officer Riley discovered a sawed-off
shotgun in the car. Mr. Laughrin was later indicted in the United States District
Court for the District of New Mexico on six weapons charges, three of which
were based on possession of the sawed-off shotgun. Mr. Laughrin moved to
suppress the gun on the ground that the traffic stop violated the Fourth
Amendment. The district court denied the motion, and Mr. Laughrin was
eventually convicted by a jury on all six counts. He appeals the denial of his
motion to suppress, contending that Officer Riley lacked reasonable suspicion to
stop his car. He also contends that the district court erred in sentencing him
when it applied a two-level enhancement for possessing a firearm with an altered
or obliterated serial number. We have jurisdiction under 28 U.S.C. § 1291 and
18 U.S.C. § 3742(a)(1). Agreeing with both of Mr. Laughrin's contentions, we
reverse and remand.

I. MOTION TO SUPPRESS

On the evening of December 31, 2001, Officer Riley recognized
Mr. Laughrin buying gas at a convenience store in Lovington. When
Mr. Laughrin drove away from the convenience store, Officer Riley followed him
for about one-half mile, during which time he observed no traffic violations.
Nevertheless, he decided to stop Mr. Laughrin. He based this decision solely on
his knowledge of Mr. Laughrin's driving record. Officer Riley testified that he
had had about 10 contacts with Mr. Laughrin during his tenure on the Lovington
police force. "Some [of these contacts] were traffic violations--no driver's
license or speeding or things like that--some were assisting other officers with
warrant service or taking reports." R. Vol. IV at 4. When asked at the
suppression hearing whether he had ever "stop[ped] Mr. Laughrin when he was
driving on a suspended license" and whether that had "happen[ed] on more than
one occasion," Officer Riley responded affirmatively but did not indicate when or
how many times it had occurred. R. Vol. IV at 5. The most recent prior
encounter must have been before Officer Riley had left for training at the police
academy 22 weeks earlier, because he had not seen Mr. Laughrin since his return.
Officer Riley also testified that "other officers had the same experience with
Mr. Laughrin," R. Vol. IV at 5, but he offered no specifics.

After Mr. Laughrin pulled to the side of the road, Officer Riley asked him
for his license, insurance, and registration. Mr. Laughrin responded that he did
not have those documents with him. Officer Riley informed Mr. Laughrin that he
had stopped him for driving with a suspended license, to which Mr. Laughrin
replied that he currently had a valid driver's license, although he did not have it
with him. While he was talking with Mr. Laughrin, Officer Riley looked inside
Mr. Laughrin's car and observed the barrel of a gun behind the driver's seat. He
then stepped back from the car, ordered Mr. Laughrin and his passenger to place
their hands on the dashboard and remain motionless, and called for a backup
police unit. When the other unit arrived, the officers directed Mr. Laughrin and
his passenger to step out of the car and placed handcuffs on them. Officer Riley
removed the gun, which turned out to be a sawed-off shotgun, from the car.
During the stop Officer Riley had informed the police radio dispatcher of
Mr. Laughrin's name and date of birth, and the dispatcher had responded that
Mr. Laughrin had a valid license.

After he was indicted by the federal grand jury, Mr. Laughrin moved to
suppress the shotgun. The district court denied the motion, stating that Officer
Riley had reasonable suspicion to stop Mr. Laughrin: "He had had, by that time,
10 prior contacts approximately with the defendant and had stopped him
previously for a suspended license. Given his prior record, it is not unreasonable
for the officer to have concluded that, again, the defendant is driving on a
suspended license." R. Vol. IV at 35-36. On appeal Mr. Laughrin argues that
Officer Riley's knowledge of his prior driving offenses was not sufficient to
create reasonable suspicion that he was driving without a valid license on the day
of the stop. We agree.

The Fourth Amendment protects the "right of the people to be secure in
their persons, houses, papers, and effects, against unreasonable searches and
seizures." U.S. Const. Amend. IV. A traffic stop is a Fourth Amendment
seizure, Delaware v. Prouse, 440 U.S. 648, 653 (1979), but it does not violate
the Fourth Amendment if it "is based on an observed traffic violation or if the
police officer has reasonable articulable suspicion that a traffic or equipment
violation has occurred or is occurring," United States v. Callarman, 273 F.3d
1284, 1286 (10th Cir. 2001) (internal quotation marks omitted). When reviewing
a district court's ruling on a motion to suppress, "we accept the trial court's
factual findings unless clearly erroneous, and view the evidence in the light most
favorable to the district court's finding." United States v. Vercher, 358 F.3d
1257, 1261 (10th Cir. 2004) (internal quotation marks and brackets omitted).
"We review de novo the ultimate determination of the reasonableness of the
[traffic] stop under the Fourth Amendment." Id. (internal quotation marks and
brackets omitted).

We recognize that reasonable suspicion is a "fluid concept[ ] that take[s]
[its] substantive content from the particular context[ ] in which [it is] being
assessed," Ornelas v. United States, 517 U.S. 690, 696 (1996), and whether there
is reasonable suspicion of criminal activity depends on the totality of the
circumstances in a particular case. United States v. Arvizu, 534 U.S. 266, 273
(2002). But "knowledge of a person's prior criminal involvement . . . is alone
insufficient to give rise to the requisite reasonable suspicion." United States v.
Sandoval, 29 F.3d 537, 542 (10th Cir. 1994). AccordUnited States v. Santos,
403 F.3d 1120, 1132 (10th Cir. 2005); United States v. Artez, 389 F.3d 1106,
1114 (10th Cir. 2004); United States v. West, 219 F.3d 1171, 1179 (10th Cir.
2000); United States v. Davis, 94 F.3d 1465, 1469 (10th Cir. 1996). "If the law
were otherwise, any person with any sort of criminal record--or even worse, a
person with arrests but no convictions--could be subjected to [an] investigative
stop by a law enforcement officer at any time without the need for any other
justification at all." Sandoval, 29 F.3d at 543. To find reasonable suspicion in
this case could violate a basic precept that law-enforcement officers not disturb a
free person's liberty solely because of a criminal record. Under the Fourth
Amendment our society does not allow police officers to "round up the usual
suspects."

It might be argued that Officer Riley had reasonable suspicion to stop
Mr. Laughrin based not on his criminal history of driving without a valid
license,
but on the ongoing violation of driving without a valid license--that
Mr. Laughrin was still engaged in the same offense that he had been stopped for
before. But whether it is reasonable to believe that Mr. Laughrin has continued
to drive without a license depends on the length of time since he was last found
to be driving without a license. Other circuits have upheld stops for driving
without a license based on the officer's knowledge that the motorist had no valid
license a week before, United States v. Hope, 906 F.2d 254, 258 (7th Cir. 1990),
or 22 days earlier, United States v. Sandridge, 385 F.3d 1032, 1036 (6th Cir.
2004). Twenty-two days is significantly less than 22 weeks. Had Officer Riley
testified to the length of the prior suspension, we might be able to affirm the
district court's determination that he had reasonable suspicion. Otherwise,
however, Officer Riley's information was too stale to justify stopping Mr.
Laughrin on the belief that a suspension was still in effect.

II. SENTENCE ENHANCEMENT

Because Mr. Laughrin does not challenge his convictions on three of the
weapons charges against him, we must now turn to his challenge to his sentence.
The shotgun that Officer Riley seized from Mr. Laughrin's car did not have a
serial number imprinted on it. It was manufactured before 1969, the year serial
numbers became required by law, see Anthony A. Braga, et al., The Illegal
Supply of Firearms, 2002 Crime & Just. 319, 322, and had never borne a serial
number. In sentencing Mr. Laughrin, however, the district court applied United
States Sentencing Guidelines (USSG) 2K2.1(b)(4), which requires a two-level
increase in the base offense level if the firearm at issue "was stolen, or had an
altered or obliterated serial number." Mr. Laughrin argues now, as he did in
district court, that the two-level increase was error because the shotgun never had
a serial number and it was thus impossible to alter or obliterate it. Mr. Laughrin
was sentenced before the Supreme Court's decision in United States v. Booker,
125 S.Ct. 738 (2005). "Therefore, we apply the pre-Booker standard of review
here." United States v. Souser, 405 F.3d 1162, 1165 (10th Cir. 2005). We
"review de novo the district court's legal interpretation of the Sentencing
Guidelines." United States v. Cardena-Garcia, 362 F.3d 663, 665 (10th Cir.
2004) (internal quotation marks, brackets, and ellipses omitted).

Both the Second and Ninth Circuits have held that the clear language of
USSG § 2K2.1(b)(4) prohibits its application when the defendant possessed a
weapon that had never borne a serial number. See United States v. Bakhtiari, 913
F.2d 1053, 1063 (2d Cir. 1990) (homemade silencer); United States v. Seesing,
234 F.3d 456, 460 (9th Cir. 2001) (same). The government challenges the
reasoning of Bakhtiari and Seesing,arguing that the
manufacturer of a weapon
who neglects to affix a serial number should be treated identically to someone
who removes a serial number from a weapon manufactured by someone else. The
court in Bakhtiari acknowledged the policy argument in favor of such equivalent
treatment but decided that it was bound by the guidelines language:

To be sure, the government's position on this score has some logical
force--a court should treat similarly on the one hand a defendant
who affirmatively obliterates a serial number and, on the other, one
who personally designs a silencer [or fashions a sawed-off shotgun]
and never affixes a serial number in the first place. We are bound,
however, by the provision the Sentencing Commission did in fact
adopt, and that provision specifically applies only to those firearms
which "[were] stolen or [have] an altered or obliterated serial
number."

Bakhtiari, 913 F.2d at 1063. We agree.

Moreover, even if we would have been inclined to disagree with the
decisions by our fellow circuits as a matter of first impression, their persuasive
force has been magnified by the Sentencing Commission's apparent agreement
with these decisions. The Sentencing Commission has amended § 2K2.1 twelve
times since Bakhtiari was decided in September 1990. See USSG
§ 2K2.1
historical note (2005). None of those amendments changed the language of
subsection (b)(4). In addition, in 1993 the Commission specifically addressed
§ 2K2.1(b)(4) by adding what is now application note 16, which states that the
§
2K2.1(b)(4) enhancement applies regardless of the defendant's knowledge that
the firearm was stolen or had an altered or obliterated serial number, but it made
no reference to firearms that never had a serial number. See id. app. C vol. I,
amd. 478 (2003). "We . . . interpret and apply the sentencing guidelines in a
manner consistent with the Sentencing Commission's intent." United States v.
O'Flanagan, 339 F.3d 1229, 1235 (10th Cir. 2003). "A fundamental rule of
statutory construction is that we presume Congress, when reenacting a statute
without change, adopts uniform judicial interpretations given a particular word,
phrase, or provision." Id. And this same approach applies when construing the
guidelines. See id. The Sentencing Commission's failure to make
any change in
the language of § 2K2.1(b)(4) in the years since Bakhtiari and
Seesing were
decided "suggest[s] that the Sentencing Commission was content with [those]
interpretation[s]." Id. at 1235.

The government also contends that United States v. Webb, 49 F.3d 636,
640 (10th Cir. 1995) (Webb I); appeal after remand, 98 F.3d 585 (10th
Cir.
1996) (Webb II), holds that the § 2K2.1(b)(4) enhancement applies to
weapons
never imprinted with serial numbers. But our opinion in that case did not address
the merits of the issue. See Webb II, 98 F.3d at 588-89.

The district court erred in applying § 2K2.1(b)(4) to Mr. Laughrin.

III. CONCLUSION

We REVERSE the district court's denial of the motion to suppress
evidence, VACATE Mr. Laughrin's sentence, and REMAND for further
proceedings in accordance with this opinion.